Legends of Tomorrow returns for its sixth season as the show’s 20th regular cast member, Esperanza “Spooner” Cruz, joins the Waverider crew, giving the show the second highest number of regular cast members in the Arrowverse - just one less than the 21 regular cast members Arrow had in its 8 seasons. Over the years the crowded character ensemble has become Legends of Tomorrow's biggest problem.
Legends premiered with 9 regular cast members. Subsequent seasons have seen that number fluctuate, as new characters were added to fill departures dictated by either actor or storyline decisions. In season 5, the roster grew to ten regulars with additional recurring characters frequenting the ship. Of its regular characters, only Sara Lance and Mick Rory remain from the original ensemble.
As the show evolved into more of a procedural, the writers of Legends of Tomorrow had difficulty juggling myriad character arcs and combining them with good storytelling. They carved their niche as the quirky Arrowverse show with offbeat figures (i.e. Beebo) and capers, such as the magical adventures that introduced John Constantine in season 4. However, with a crowded revolving door of characters being used mostly for their respective gimmicks, they don't seem to know how to effectively use most of those characters, often failing to provide meaningful challenges. Legends of Tomorrow now focuses instead on developing only one character at a time, usually in arcs rushed or condensed to give other characters on the show something to do.
Having so many characters circulate through the Waverider has both helped and hurt Legends of Tomorrow. Some, such as Hawkgirl and Hawkman in season 1 and Kid Flash in season 3, did not connect with the fans or lacked a strong storyline, and were easy to write out. Popular characters like Leonard Snart, Martin Stein, and Jax left a greater void. Mona and Gary, brought in for primarily comic relief, work well about half the time. The crowded cast list also brought about uneven writing for solid characters such as Nate and Ray. Nate has been reduced somewhat to the ship Lothario, whose relationships with fellow crew members result either in death or erasure of memories, like what happened with Amaya and Zari. Ray Palmer's character arc has been all over the place; despite an interesting dynamic between him and Eobard Thawne in season 2, he has faced few internal conflicts.
Conversely, the departure of the Legends' original leader Rip Hunter facilitated the show’s strongest character arc: Sara Lance’s growth from assassin to ship captain. Bringing Ava on board the Waverider full time in season 5 was also a good move. Making the coarse thief/part-time romance author Mick Rory a father in season 5 was an inspired, satisfying development. The additions of the charismatic Zari in season 3 and her brother, Behrad (who becomes a cast regular in season 6), were also a huge boost. Another brilliant twist was bringing Nora Darkh onto the Waverider, reintroducing the foes-turned-frenemies conflict between Sara and Damien Dahrk - a dynamic the show should implement more often. Nora was also integral in redeeming Ray's wandering storyline when those two fell in love.
Legends of Tomorrow season 6 looks to stay true to its form of tying new characters to its villains, which works for the flavor-of-the-month storytelling. With the theme set to be battling aliens this season, the new character “Spooner” is an expert on aliens who purportedly has telepathic abilities brought about by her alien abduction. The success of Spooner's introduction to Legends will depend on how quickly the show is able to connect viewers with her, and whether they'll be able to give her enough time to properly develop amid an already stacked ensemble.